Eliminating and/or reducing the number of Runway Incursions and Surface Incidents is a primary objective of the FAA and the NTSB. In fact, the world's worst commercial airline disaster occurred on a runway on Mar. 27, 1977. Numerous accidents have been caused because a pilot (or pilots) did not know their exact position, and sometimes aircraft taking off from taxiways. 43% of pilots responsible for runway incursions reported a temporary loss of positional awareness—FAA Runway Safety Report—August 2005.
Each runway has numbers painted on it that designate the ‘runway name’ and its approximate magnetic heading. For example, runway 31 is very closely aligned with a magnetic heading of 310°. These runway numbers help pilots taxiing or landing identify and verify the appropriate runway. Sometimes, however, these numbers can be located thousands of feet from a runway entry point and can often be located behind an aircraft taxiing onto a runway at a runway/taxiway intersection. These runway numbers are also difficult to see from a ground location other than directly in front of them. Runways are usually constructed from the same material as adjacent taxiways and it is almost impossible to distinguish where a runway meets a taxiway.
Airports often have a tremendous amount of signage and lighting to aid a pilot's situational awareness. Lighting and signage become progressively more difficult to see as the ambient light decreases at night and in bad visibility conditions. In some cases pilots have taken off from a taxiway adjacent to a runway thinking that they were on the runway. Incidents like these have resulted in accidents with the loss of life. Aircraft taxiing onto an active runway often results in the loss of separation of aircraft and a potentially very dangerous situation.
There are various technologies currently in service or being tested. Some solutions include having an airport layout definition database. However each time an airport layout is modified, taxiways or runways renamed, or lighting systems modified, this database must be updated. Moreover, since this database is aimed at commercial airliners, it only includes the larger airports that are serviced by the larger airlines. Other systems, for example the Ground Marker Program, require equipment on the airport surface that notifies aircraft when they physically activate them. These systems consist of any number of antennae, transmitters, inductive loops and computers. As the airport complexity increases, so too does the cost of the system because additional equipment needs to be placed at each additional location. Such devices are aimed at the ‘situational awareness’ of the pilot; i.e. having a pilot knowing their exact position on the airport. Each of the above-mentioned systems has a cost associated with them in updating the airport definition database, or the purchase and installation of transmitters in the airport and purchase and installation and maintenance of receivers in each and every aircraft. General Aviation pilots, who often do not have access to the above mentioned systems, perform most of the United States' take-offs and landings, and large airlines service only a small percentage of the nation's airports. Also, non-aircraft vehicles account for a non-trivial percentage of surface incidents. These vehicles do not carry advanced avionics, nor do they carry the 75 MHz equipment required for the Ground Marker Program.
Determining the location of other aircraft and vehicles can be extremely difficult and very often impossible in night and/or reduced visibility conditions. Low clouds, fog, haze, and other meteorological conditions can reduce visibility to very short distances. Reduced visibility becomes a serious problem for both pilots of aircraft and tower personel. Pilots need to know if there is an aircraft on or about to enter a runway, and Air Traffic Controllers need to be able to determine the location of aircraft and vehicles on and around the airport.
In view of the foregoing, there is a need for a system for improving a pilot's situational awareness and an Air Traffic Controller's awareness of the airport traffic that is desirably less costly than existing systems and, further, desirably available to smaller airports and general aviation pilots.
Unless otherwise indicated illustrations in the figures are not necessarily drawn to scale.